Observation of the Einstein-de Haas Effect in a Bose-Einstein condensate

The Einstein-de Haas effect is a phenomenon in which angular momentum is transferred from microscopic spins to mechanical rotation of a rigid body. Here, we report the first observation of the Einstein-de Haas effect in a spinor-dipolar Bose-Einstein condensate where quantized vortices emerge in depolarized spinor components through coherent angular-momentum transfer from microscopic atomic spins to macroscopic quantized circulation. Experimental results clearly show that the spherical symmetry of the condensate is dynamically broken into the axisymmetry by an intrinsic magnetic dipole-dipole interaction.